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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:37:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:37:10 +0000 |
commit | c9addba5cc770d2d231b34f6739f32c6be8690f1 (patch) | |
tree | c643da154a95a1d163137135050bb47858a1654e /gl/lib/windows-once.c | |
parent | Initial commit. (diff) | |
download | man-db-c9addba5cc770d2d231b34f6739f32c6be8690f1.tar.xz man-db-c9addba5cc770d2d231b34f6739f32c6be8690f1.zip |
Adding upstream version 2.12.0.upstream/2.12.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gl/lib/windows-once.c')
-rw-r--r-- | gl/lib/windows-once.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/gl/lib/windows-once.c b/gl/lib/windows-once.c new file mode 100644 index 0000000..0d28281 --- /dev/null +++ b/gl/lib/windows-once.c @@ -0,0 +1,62 @@ +/* Once-only control (native Windows implementation). + Copyright (C) 2005-2023 Free Software Foundation, Inc. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Bruno Haible <bruno@clisp.org>, 2005. + Based on GCC's gthr-win32.h. */ + +#include <config.h> + +/* Specification. */ +#include "windows-once.h" + +#include <stdlib.h> + +void +glwthread_once (glwthread_once_t *once_control, void (*initfunction) (void)) +{ + if (once_control->inited <= 0) + { + if (InterlockedIncrement (&once_control->started) == 0) + { + /* This thread is the first one to come to this once_control. */ + InitializeCriticalSection (&once_control->lock); + EnterCriticalSection (&once_control->lock); + once_control->inited = 0; + initfunction (); + once_control->inited = 1; + LeaveCriticalSection (&once_control->lock); + } + else + { + /* Don't let once_control->started grow and wrap around. */ + InterlockedDecrement (&once_control->started); + /* Some other thread has already started the initialization. + Yield the CPU while waiting for the other thread to finish + initializing and taking the lock. */ + while (once_control->inited < 0) + Sleep (0); + if (once_control->inited <= 0) + { + /* Take the lock. This blocks until the other thread has + finished calling the initfunction. */ + EnterCriticalSection (&once_control->lock); + LeaveCriticalSection (&once_control->lock); + if (!(once_control->inited > 0)) + abort (); + } + } + } +} |